A large market exists for magnetic hard disk drives for mass-market host computer systems such as servers, desktop computers and laptop computers. To be competitive in this market, a hard disk drive must be relatively inexpensive and must accordingly embody a design that is adapted for low cost mass production.
A significant cost adder to hard disk drives is the need to write servo-data-track segments on the tracks of the disk before user-data may be written to the disk. Servo-data track segments allow the hard disk drive to determine where the read/write head of the disk drive is relative to the disk surface. Servo-track segments are written to hard-drive disks in clean rooms by servo-track-writers. A clean room is necessary to prevent foreign material falling on the disk surface. At the extremely high speeds that the disk spins at and given the extremely small distance between the surface of the magnetic disk and the read/write head of the hard-disk drive, very small amounts of foreign material can lead to hard disk drive failure. Additionally, servo track writers are expensive pieces of equipment.
Given the competitive market, any technique that will reduce the cost of manufacturing hard-disk drives and especially reduce the cost of writing servo-data would provide an important competitive advantage.